Carbohydrate Polymers最新文献

Polysaccharide-based edible films have been widely developed as food packaging materials in response to the rising environmental concerns caused by the extensive use of plastic packaging. In recent years, the integration of carboxymethyl cellulose (CMC) and chitosan (CS) for a binary edible film has received considerable interest because this binary edible film can retain the advantages of both constituents (e.g., the great oxygen barrier ability of CMC and moderate antimicrobial activity of CS) while mitigating their respective disadvantages (e.g., the low water resistance of CMC and poor mechanical strength of CS). This review aims to present the latest advancements in CMC–CS edible films. The preparation methods and properties of CMC–CS edible films are comprehensively introduced. Potential additives and technologies utilized to enhance the properties are discussed. The applications of CMC–CS edible films on food products are summarized. Literature shows that the current preparation methods for CMC–CS edible film are solvent-casting (main) and thermo-mechanical methods. The CMC–CS binary films have superior properties compared to films made from a single constituent. Moreover, some properties, such as physical strength, antibacterial ability, and antioxidant activity, can be greatly enhanced via the incorporation of some bioactive substances (e.g. essential oils and nanomaterials). To date, several applications of CMC–CS edible films in vegetables, fruits, dry foods, dairy products, and meats have been studied. Overall, CMC–CS edible films are highly promising as food packaging materials.

Integrating flexible piezoelectric nanogenerators (PENGs) into wearable and portable electronics offers promising prospects for motion monitoring. However, it remains a significant challenge to develop environmentally friendly PENGs using biodegradable and cost-effective natural polymers for mechanical energy harvesting and self-powered sensing. Herein, reduced graphene oxide (rGO) and barium titanate (BTO) were introduced into regenerated cellulose pulp to fabricate a composite porous film-based PENG. The incorporation of rGO not only increased the electrical conductivity of the porous film but also enhanced the dispersibility of BTO. Moreover, the unique pore structure of the composite porous film improved the polarization effect of the air inside the pores, thereby greatly boosting the overall piezoelectric performance. The piezoelectric coefficient of the resulting composite porous film reaches up to 41.5 pC·N⁻¹, which is comparable to or higher than those reported in similar studies. Consequently, the PENG assembled from this cellulose/rGO/BTO composite porous film (CGB-PENG) achieved an output voltage of 47 V, a current of 4.6 μA, and a power density of 30 μW·cm⁻², approximately three times the output voltage and ten times the power density of similar studies. This work presents a feasible approach for the fabrication of high-performance cellulose-based PENGs derived from recycled waste cotton textiles.

Traditional Fenton principles for degrading polysaccharides, including chondroitin sulfate (CS), are fraught with limitations, such as strict pH-dependence, higher temperature requirements, desulfurization, and environmentally perilous. In this study, an effective Fenton-like system comprising trimetallic-doped carbon nitride material (tri-CN) with hydrogen-bonded melamine-cyanuric acid (MCA) supramolecular aggregates as its basic skeleton was engineered to overcome the challenges of traditional methods. Detailed material characterizations revealed that, compared to monometallic-doped or bimetallic-doped counterparts, tri-CN offered a larger surface area, higher porosity, and increased metal loading, thereby enhancing reactant accessibility and polysaccharide degradation efficiency. The characterization and activity assessment of the degraded polysaccharide revealed structurally intact products without significant desulfurization, indicating the effectiveness of the designed approach. Moreover, the degraded chondroitin sulfate CS3 catalyzed by tri-CN, exhibited promising antioxidant activity and anti-CRISPR potential. The results elucidated that the high-valent iron species in the material served as primary active sites, catalyzing the cleavage of hydrogen peroxide to generate hydroxyl radicals that subsequently attacked CS chains, leading to their fragmentation. Hence, the designed material can be efficiently applied to polysaccharide degradation, but not limited to photocatalysis, electrocatalysis, sensor, energy storage materials, and wastewater treatment.

Bone defects caused by trauma, infection and congenital diseases still face great challenges. Dihydromyricetin (DHM) is a kind of flavone extracted from Ampelopsis grossedentata, a traditional Chinese medicine. DHM can enhance the osteogenic differentiation of human bone marrow mesenchymal stem cells with the potential to promote bone regeneration. Hydrogel can be used as a carrier of DHM to promote bone regeneration due to its unique biochemical characteristics and three-dimensional structure. In this study, oxidized phellinus igniarius polysaccharides (OP) and L-arginine chitosan (CA) are used to develop hydrogel. The pore size and gel strength of the hydrogel can be changed by adjusting the oxidation degree of oxidized phellinus igniarius polysaccharides. The addition of DHM further reduce the pore size of the hydrogel (213 μm), increase the mechanical properties of the hydrogel, and increase the antioxidant and antibacterial activities of the hydrogel. The scavenging rate of DPPH are 72.30 ± 0.33 %, and the inhibition rate of E.coli and S.aureus are 93.12 ± 0.38 % and 94.49 ± 1.57 %, respectively. In addition, PCAD has good adhesion and biocompatibility, and its extract can effectively promote the osteogenic differentiation of MC3T3-E1 cells. Network pharmacology and molecular docking show that the promoting effect of DHM on osteogenesis may be achieved by activating the PI3K/AKT and MAPK signaling pathways. This is confirmed through in vitro cell experiments and in vivo animal experiments.

This study investigates the complexation between tea seed starch (TSS) and tea polyphenols (TPs) at varying concentrations (2.5, 5.0, 7.5, and 10.0 %). The objectives can expand the knowledge of TSS, which is a novel starch, and to examine how TPs influence the structure and physicochemical properties of the complexes. Results indicate that TPs interact with TSS through hydrogen bonding, altering granule morphology and disrupting ordered structure of starch. Depending on the concentration, TPs induce either V-type or non-V-type crystal structures within TSS, which had bearing on iodine binding capacity, swelling, pasting, gelatinization, retrogradation, rheology, and gel structure. In vitro digestibility analysis reveals that TSS-TPs complexes tend to reduce readily digestible starch while increasing resistant starch fractions with higher TP concentrations. Thus, TSS-TPs complexes physicochemical and digestibility properties can be modulated, providing a wide range of potential applications in the food industry.

Burns are the fourth most common type of civilian trauma worldwide, and the management of severe irregular scald wounds remains a significant challenge. Herein, crocin-1 laden hydroxybutyl chitosan (CRO-HBC) thermosensitive hydrogel with smart anti-inflammatory performance was developed for accelerating full-thickness burn healing. The injectable and shape adaptability of the CRO-HBC gel make it a promising candidate for effectively filling scald wounds with irregular shapes, while simultaneously providing protection against external pathogens. The CRO-HBC gel network formed by hydrophobic interactions exhibited an initial burst release of crocin-1, followed by a gradual and sustained release over time. The excessive release of ROS and pro-inflammatory cytokines should be effectively regulated in the early stage of wound healing. The controlled release of crocin-1 from the CRO-HBC gel adequately addresses this requirement for wound healing. The CRO-HBC hydrogel also exhibited an excellent biocompatibility, an appropriate biodegradability, keratinocyte migration facilitation properties, and a reactive oxygen species scavenging capability. The composite CRO-HBC hydrogel intelligently mitigated inflammatory responses, promoted angiogenesis, and exhibited a commendable efficacy for tissue regeneration in a full-thickness scalding model. Overall, this innovative temperature-sensitive CRO-HBC injectable hydrogel dressing with smart anti-inflammatory performance has enormous potential for managing severe scald wounds.

Aiming at dealing with organic and inorganic pollutants dissolved in aquatic environments, we introduce self-assembled fluorescent nanocomposite hydrogel based on a binary polysaccharide network (xanthan gum/chitosan) embedding nitrogen-doped carbon quantum dots not only as a hybrid solid optical sensor for detecting Cr(VI) ions but also to remove anionically charged contaminants Cr(VI) and methyl orange (MO) by acting as an adsorbent. This fluorescent nanocomposite achieved a detection limit of 0.29 μM when used to detect Cr(VI) and demonstrated a fluorescence quantum yield of 59.7 %. Several factors contributed to the effectiveness of the adsorption of Cr(VI) and MO in batch studies, including the solution pH, dosage of the adsorbent, temperature, initial contamination level, and contact time. Experimental results showed 456 mg/g maximum adsorption capacity at pH 4 for MO compared to 291 mg/g at pH 2 for Cr(VI) at 25 °C. In addition to conforming to Langmuir's model, Cr(VI) and MO's adsorption kinetics closely matched pseudo-second-order. Using thermodynamic parameters, the results indicate that Cr(VI) and MO adsorb spontaneously and exothermically. Recycling spent adsorbent for Cr(VI) and MO using NaOH at 0.1 M was possible; the respective adsorption efficiency remained at approximately 82.2 % and 83 % after the fifth regeneration cycle.

A novel photocatalytic adsorbent, a cellulose nanofibrils based hydrogel incorporating carbon dots and Bi₂O₃/BiOCOOH (designated as CCHBi), was developed to address lignin pollution. CCHBi exhibited an adsorption capacity of 435.0 mg/g, 8.9 times greater than that of commercial activated carbon. This enhanced adsorption performance was attributed to the 3D porous structure constructed using cellulose nanofibrils (CNs), which increased the specific surface area and provided additional sorption sites. Adsorption and photocatalytic experiments showed that CCHBi had a photocatalytic degradation rate constant of 0.0140 min⁻¹, 3.1 times higher than that of Bi₂O₃/BiOCOOH. The superior photocatalytic performance of CCHBi was due to the Z-scheme photocatalytic system constructed by carbon dots-loaded cellulose nanofibrils and Bi₂O₃/BiOCOOH, which facilitated the separation of photoinduced charge carriers. Additionally, the stability of CCHBi was confirmed through consecutive cycles of adsorption and photocatalysis, maintaining a removal efficiency of 85 % after ten cycles. The enhanced stability was due to the 3D porous structure constructed by CNs, which safeguarded the Bi₂O₃/BiOCOOH. This study validates the potential of CCHBi for high-performance lignin removal and promotes the application of CNs in developing new photocatalytic adsorbents.

Rational designs of polysaccharide-based hydrogels with organ-like three-dimensional architecture provide a great possibility for addressing the shortages of allograft tissues and organs. However, spatial-temporal control over structure in bulk hydrogel and acquire satisfied mechanical properties remain an intrinsic challenge to achieve. Here, we show how electric-field assisted molecular self-assembly can be coupled to a directional reaction-diffusion (RD) process to produce macroscopic hydrogel in a controllable manner. The electrical energy input was not only to generate complex molecule gradients and initiate the molecular self-assembly, but also to guide/facilitate the RD processes for the gel rapid growth via a cascade construction interaction. The hydrogel mechanical properties can be tuned and enhanced by using an interpenetrating biopolymer network and multiple ionic crosslinkers, leading to a wide-range of mechanical modulus to match with biological organs or tissues. We demonstrate diverse 3D macroscopic hydrogels can be easily prepared via field-assisted directional reaction-diffusion and specific joint interactions. The humility-triggered dissipation of functional gradients and antibacterial performance confirm that the hydrogels can serve as an optically variable soft device for wound management. Therefore, this work provides a general approach toward the rational fabrication of soft hydrogels with controlled architectures and functionality for advanced biomedical systems.

Conductive hydrogels have been widely used in wearable electronics due to their flexible, conductive and adjustable properties. With ever-growing demand for sustainable and biocompatible sensing materials, biopolymer-based hydrogels have drawn significant attention. Among them, starch-based hydrogels have a great potential for wearable electronics. However, it remains challenging to develop multifunctional starch-based hydrogels with high stretchability, good conductivity, excellent durability and high sensitivity. Herein, amylopectin and ionic liquid were introduced into a hydrophobic association hydrogel to endow it with versatility. Benefiting from the synergistic effect of amylopectin and ionic liquid, the hydrogel exhibited excellent mechanical properties (the elongation of 2540 % with a Young's modulus of 12.0 kPa and a toughness of 1.3 MJ·m⁻³), self-recovery, good electrical properties (a conductivity of 1.8 S·m⁻¹ and electrical self-healing), high sensitivity (gauge factor up to 26.85) and excellent durability (5850 cycles). The above properties of the hydrogel were closely correlated to its internal structure from hydrophobic association, H-bonding and electrostatic interaction, and can be regulated by changing the component contents. A wireless wearable sensor based on the hydrogel realized accurate and stable monitoring of joint motions and expression changes. This work demonstrates a kind of promising biopolymer-based materials as candidates for high-performance flexible wearable sensors.